The principal objectives of this proposal are to develop methodology for stereospecific synthesis of 1,2- and 1,3-diol derivatives and 1,3-dimethyl derivatives through the use of allylboranes and to carry out the synthesis of ionomycin, a highly selective calcium ion ionophore. Allylboranes will be prepared from the more readily accessible allylsilanes which will allow synthesis of a variety of substituted derivatives as well. These derivatives will be employed in the stereorational synthesis of ionomycin and a variety of analogs. The successful culmination of this work would open new vistas for the synthesis of a variety of other biologically significant molecules such as the ansa, macrolide and other ionophore antibiotics.